Gynaecologist Dr Gedis Grudzinskas said it would make them “more happy and comfortable” and be positive for employers.

But critics claimed small businesses would be crippled — or would chose to employ men. The row comes after a survey of 1,000 women for the BBC found 52 per cent had suffered cramps so severe it affected their ability to work.

Only 27 per cent told their boss that period pain was responsible, with many choosing to “suffer in silence”.

Dr Grudzinskas said: “Some women suffer terribly. I don’t think they should be shy about it, and companies should be accommodating. If women feel supported, it will be a happy and productive workforce.”

Gynaecologist Dr Gedis Grudzinskas said providing menstrual leave would benefit employers

Employment lawyer Fiona Morrison, of Brodies LLP in Aberdeen, said severe period pains could even be considered a disability.

She explained: “If someone is in extreme pain and it is stopping them from working effectively, a tribunal could say that this woman is disabled. It is judged on the impact on the woman without treatment or painkillers.”

But she added: “It would always be case specific, so I can’t see it opening the floodgates on claims.”

The Institute of Directors said: “It’s up to individual employers how they respond to these issues. We’d urge employers to demonstrate they are open to conversations around both physical and mental health.”

And the Confederation of British Industry added: “Firms must seek to balance their employees’ needs with those of their business.”

Some Eastern countries, such as Japan, can already grant women “menstrual leave”.